Fractionally Spaced Equalization of Nonlinear Channels

分数间隔均衡（FSE）已成为许多研究关注的焦点，因为发现分数采样的信道输出允许其识别从二阶统计的信道输出下一般满足的条件。在衰落多径环境中，信道动态的频繁变化使得训练信号非常浪费，因此需要盲方案。大部分的盲分数间隔均衡文献都致力于线性信道。然而，许多信道，如卫星和微波信道与非线性放大器，水下和磁记录信道是固有的非线性。如果放大器在其最功率有效的状态下操作，则尤其如此。此外，在光纤通信中，具有丰富的带宽，最大的挑战是由信道中的色散非线性引起的。在许多这样的情况下，盲均衡是自然的，它是重要的是要考虑盲FSE的非线性channel.This研究涉及的FIR信道的盲分数间隔均衡的特点是基带信道的输出是一个多项式函数的当前和过去的输入值。所寻求的均衡器也属于这类。利用非线性系统互质性的概念，并采用差分代数技术，对这类信道的均衡进行了基本的研究。条件下，这些渠道是平等的，并可以确定的二阶统计的输出正在探索。采用统计和确定性方法。直接和间接均衡器的设计方法制定。设计了迫零均衡器和最小均方误差均衡器。使用子空间方法。自适应方案的假设。基本存在的问题，以及实际的设计问题被认为是。

Fractionally Spaced Equalization (FSE) has become the focus of much research attention since the discovery that fractionally sampling the output of a channel permits its identification from the second-order statistics of the channel output under generically satisfied conditions. Blind schemes in turn are desirable in fading multipath environments where frequent changes in the channel dynamics, makes training signals very wasteful. Most of the blind Fractionally Spaced Equalization literature has been devoted to linear channels. Yet many channels such as satellite and microwave channels with nonlinear amplifiers, underwater and magnetic recording channels are inherently nonlinear. This is particularly so if the amplifiers operate in their most power efficient regimes. Further, in fiber optical communications, having an abundant bandwidth, the greatest challenge, is posed by dispersive nonlinearities in the channel. In many such instances blind equalization is natural and it is important to consider blind FSE of nonlinear channels.This study concerns the blind Fractionally Spaced Equalization of FIR channels characterized by a baseband channel output that is a polynomial function of the current and past values of the input. The equalizers sought also belong to this class. Using the concept of coprimeness of nonlinear systems, and employing difference algebraic techniques, a fundamental investigation into the equalization of this class of channels is being conducted. Conditions under which these channels are equalizable, and can be identified by the second order statistics of the output are being explored. Statistical and deterministic methods are employed. Direct and indirect equalizer design methodologies are formulated. Zero Forcing and Minimum Mean Squared Error equalizers are designed. Subspace methods are used. Adaptive schemes are postulated. Fundamental existence issues as well practical design issues are considered.